ui-snapshot.c

   1 /* ui-snapshot.c: generate snapshot of a commit
   2  *
   3  * Copyright (C) 2006 Lars Hjemli
   4  * Copyright (C) 2012 Jason A. Donenfeld <Jason@zx2c4.com>
   5  *
   6  * Licensed under GNU General Public License v2
   7  *   (see COPYING for full license text)
   8  */
   9
  10 #include "cgit.h"
  11 #include "ui-snapshot.h"
  12 #include "html.h"
  13 #include "ui-shared.h"
  14
  15 static int write_archive_type(const char *format, const char *hex, const char *prefix)
  16 {
  17         struct argv_array argv = ARGV_ARRAY_INIT;
  18         const char **nargv;
  19         int result;
  20         argv_array_push(&argv, "snapshot");
  21         argv_array_push(&argv, format);
  22         if (prefix) {
  23                 struct strbuf buf = STRBUF_INIT;
  24                 strbuf_addstr(&buf, prefix);
  25                 strbuf_addch(&buf, '/');
  26                 argv_array_push(&argv, "--prefix");
  27                 argv_array_push(&argv, buf.buf);
  28                 strbuf_release(&buf);
  29         }
  30         argv_array_push(&argv, hex);
  31         /*
  32          * Now we need to copy the pointers to arguments into a new
  33          * structure because write_archive will rearrange its arguments
  34          * which may result in duplicated/missing entries causing leaks
  35          * or double-frees in argv_array_clear.
  36          */
  37         nargv = xmalloc(sizeof(char *) * (argv.argc + 1));
  38         /* argv_array guarantees a trailing NULL entry. */
  39         memcpy(nargv, argv.argv, sizeof(char *) * (argv.argc + 1));
  40
  41         result = write_archive(argv.argc, nargv, NULL, 1, NULL, 0);
  42         argv_array_clear(&argv);
  43         free(nargv);
  44         return result;
  45 }
  46
  47 static int write_tar_archive(const char *hex, const char *prefix)
  48 {
  49         return write_archive_type("--format=tar", hex, prefix);
  50 }
  51
  52 static int write_zip_archive(const char *hex, const char *prefix)
  53 {
  54         return write_archive_type("--format=zip", hex, prefix);
  55 }
  56
  57 static int write_compressed_tar_archive(const char *hex,
  58                                         const char *prefix,
  59                                         char *filter_argv[])
  60 {
  61         int rv;
  62         struct cgit_filter f;
  63
  64         f.cmd = filter_argv[0];
  65         f.argv = filter_argv;
  66         cgit_open_filter(&f);
  67         rv = write_tar_archive(hex, prefix);
  68         cgit_close_filter(&f);
  69         return rv;
  70 }
  71
  72 static int write_tar_gzip_archive(const char *hex, const char *prefix)
  73 {
  74         char *argv[] = { "gzip", "-n", NULL };
  75         return write_compressed_tar_archive(hex, prefix, argv);
  76 }
  77
  78 static int write_tar_bzip2_archive(const char *hex, const char *prefix)
  79 {
  80         char *argv[] = { "bzip2", NULL };
  81         return write_compressed_tar_archive(hex, prefix, argv);
  82 }
  83
  84 static int write_tar_xz_archive(const char *hex, const char *prefix)
  85 {
  86         char *argv[] = { "xz", NULL };
  87         return write_compressed_tar_archive(hex, prefix, argv);
  88 }
  89
  90 const struct cgit_snapshot_format cgit_snapshot_formats[] = {
  91         { ".zip", "application/x-zip", write_zip_archive, 0x01 },
  92         { ".tar.gz", "application/x-gzip", write_tar_gzip_archive, 0x02 },
  93         { ".tar.bz2", "application/x-bzip2", write_tar_bzip2_archive, 0x04 },
  94         { ".tar", "application/x-tar", write_tar_archive, 0x08 },
  95         { ".tar.xz", "application/x-xz", write_tar_xz_archive, 0x10 },
  96         { NULL }
  97 };
  98
  99 static const struct cgit_snapshot_format *get_format(const char *filename)
 100 {
 101         const struct cgit_snapshot_format *fmt;
 102         int fl, sl;
 103
 104         fl = strlen(filename);
 105         for (fmt = cgit_snapshot_formats; fmt->suffix; fmt++) {
 106                 sl = strlen(fmt->suffix);
 107                 if (sl >= fl)
 108                         continue;
 109                 if (!strcmp(fmt->suffix, filename + fl - sl))
 110                         return fmt;
 111         }
 112         return NULL;
 113 }
 114
 115 static int make_snapshot(const struct cgit_snapshot_format *format,
 116                          const char *hex, const char *prefix,
 117                          const char *filename)
 118 {
 119         unsigned char sha1[20];
 120
 121         if (get_sha1(hex, sha1)) {
 122                 cgit_print_error("Bad object id: %s", hex);
 123                 return 1;
 124         }
 125         if (!lookup_commit_reference(sha1)) {
 126                 cgit_print_error("Not a commit reference: %s", hex);
 127                 return 1;
 128         }
 129         ctx.page.mimetype = xstrdup(format->mimetype);
 130         ctx.page.filename = xstrdup(filename);
 131         cgit_print_http_headers(&ctx);
 132         format->write_func(hex, prefix);
 133         return 0;
 134 }
 135
 136 /* Try to guess the requested revision from the requested snapshot name.
 137  * First the format extension is stripped, e.g. "cgit-0.7.2.tar.gz" become
 138  * "cgit-0.7.2". If this is a valid commit object name we've got a winner.
 139  * Otherwise, if the snapshot name has a prefix matching the result from
 140  * repo_basename(), we strip the basename and any following '-' and '_'
 141  * characters ("cgit-0.7.2" -> "0.7.2") and check the resulting name once
 142  * more. If this still isn't a valid commit object name, we check if pre-
 143  * pending a 'v' or a 'V' to the remaining snapshot name ("0.7.2" ->
 144  * "v0.7.2") gives us something valid.
 145  */
 146 static const char *get_ref_from_filename(const char *url, const char *filename,
 147                                          const struct cgit_snapshot_format *format)
 148 {
 149         const char *reponame;
 150         unsigned char sha1[20];
 151         struct strbuf snapshot = STRBUF_INIT;
 152         int result = 1;
 153
 154         strbuf_addstr(&snapshot, filename);
 155         strbuf_setlen(&snapshot, snapshot.len - strlen(format->suffix));
 156
 157         if (get_sha1(snapshot.buf, sha1) == 0)
 158                 goto out;
 159
 160         reponame = cgit_repobasename(url);
 161         if (prefixcmp(snapshot.buf, reponame) == 0) {
 162                 const char *new_start = snapshot.buf;
 163                 new_start += strlen(reponame);
 164                 while (new_start && (*new_start == '-' || *new_start == '_'))
 165                         new_start++;
 166                 strbuf_splice(&snapshot, 0, new_start - snapshot.buf, "", 0);
 167         }
 168
 169         if (get_sha1(snapshot.buf, sha1) == 0)
 170                 goto out;
 171
 172         strbuf_insert(&snapshot, 0, "v", 1);
 173         if (get_sha1(snapshot.buf, sha1) == 0)
 174                 goto out;
 175
 176         strbuf_splice(&snapshot, 0, 1, "V", 1);
 177         if (get_sha1(snapshot.buf, sha1) == 0)
 178                 goto out;
 179
 180         result = 0;
 181         strbuf_release(&snapshot);
 182
 183 out:
 184         return result ? strbuf_detach(&snapshot, NULL) : NULL;
 185 }
 186
 187 __attribute__((format (printf, 1, 2)))
 188 static void show_error(char *fmt, ...)
 189 {
 190         va_list ap;
 191
 192         ctx.page.mimetype = "text/html";
 193         cgit_print_http_headers(&ctx);
 194         cgit_print_docstart(&ctx);
 195         cgit_print_pageheader(&ctx);
 196         va_start(ap, fmt);
 197         cgit_vprint_error(fmt, ap);
 198         va_end(ap);
 199         cgit_print_docend();
 200 }
 201
 202 void cgit_print_snapshot(const char *head, const char *hex,
 203                          const char *filename, int snapshots, int dwim)
 204 {
 205         const struct cgit_snapshot_format* f;
 206         char *prefix = NULL;
 207
 208         if (!filename) {
 209                 show_error("No snapshot name specified");
 210                 return;
 211         }
 212
 213         f = get_format(filename);
 214         if (!f) {
 215                 show_error("Unsupported snapshot format: %s", filename);
 216                 return;
 217         }
 218
 219         if (!hex && dwim) {
 220                 hex = get_ref_from_filename(ctx.repo->url, filename, f);
 221                 if (hex == NULL) {
 222                         html_status(404, "Not found", 0);
 223                         return;
 224                 }
 225                 prefix = xstrdup(filename);
 226                 prefix[strlen(filename) - strlen(f->suffix)] = '\0';
 227         }
 228
 229         if (!hex)
 230                 hex = head;
 231
 232         if (!prefix)
 233                 prefix = xstrdup(cgit_repobasename(ctx.repo->url));
 234
 235         make_snapshot(f, hex, prefix, filename);
 236         free(prefix);
 237 }